(US5143835-A)      Methanosarcina alcaliphilum NY-728 (FERM BP-2309) is a new bacterial strain isolated from alkaline soils that exhibits optimum growth under alkaline conditions (pH about 8.1-9.7), generating methane.    USE -   Prodn. of methane comprises propagation of Methanosarcina alcaliphilum (FERM BP-2309) in an alkaline nutrient (pH 8.1-8.7) at 15-44C (pref. 34-42 C) in the presence of MeOH or MeNH as precursor; then further propagation in the presence of HOAc, acetates, or H2-CO2 mixts.; and recovery of the methane generated    (JP93002308-B)      Methanosarcina alcaliphilum has pref. pH to grow at pH 8.1-8.7.    USE/ADVANTAGE -   Used for efficient methanation to generate biogas. Ferment methane in alkaline environment and at up to 37 deg.C. Biomethanation using Methanosarcina alcaliphilum needs no pH conditioner.    In an example, methanosarcina alcaliphilum grows at pH 7.1-9.2, pref. pH 8.1-8.7, and has methane generation activity at 15-45 (34-42) deg.C. A cell is a sphere of 1.7-2.7 micron dia.. It is a non-sporogenous, gram-positive, anaerobic bacterium which does not show susceptibility to antibiotics of inhibitor to compose peptide glycan at cell wall and has ether linkage. It can generate methane gas by hydrogen, carbon dioxide, acetic acid, methanol and methylamine as substrate. When methanol is used as substrate, the generation time is 4 hrs. shorter than by other substrates. (J01225480-A    (JP94047120-B2)      Alkaliphilic, methanogenic Methanosarcina alcaliphilum bacteria are claimed which have an optimum growth pH of 8.1-8.7. The M. alcaliphilum (NY-728) FERM BP-2309 strain is specifically claimed.    Also claimed is a methane fermentation method by culturing methanogenic bacteria in a medium contg. substrates of low assimilation rate, the characteristic features being that (i) the bacteria can assimilate at least two different substrates at different rates and (ii) the culture is in presence of both low assimilation rate substrates and substrates of high assimilation rate. The bacteria used are pref. those of the genus Methanosarcina, esp. the above novel M. alcaliphilum bacteria.    USE/ADVANTAGE -   The methane fermentation can be a process for treating solid waste or waste water. The novel bacteria are resistant to low temps. and they allow bio-methanation at an alkaline pH and at low temp., allowing bacteria concn. to be increased within a very short time so that relatively small reactors can be used. In addn. to being alkaliphilic, these novel bacteria can use substrates other than H2 and CO2.